Pre–mass extinction decline of latest Permian ammonoids

The devastating end-Permian mass extinction is widely considered to have been caused by large-scale and rapid greenhouse gas release by Siberian magmatism. Although the proximate extinction mechanisms are disputed, there is widespread agreement that a major extinction pulse occurred immediately below the biostratigraphically defined Permian–Triassic boundary. Our statistical analyses of stratigraphic confidence intervals do not comply with a...